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| INT WINAPI InetGetLocalAddress( |
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SOCKET hSocket, |
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INT nAddressFamily, |
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LPINTERNET_ADDRESS lpAddress, |
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UINT* lpnPort |
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The InetGetLocalAddress function returns the local IP
address and port number for the specified socket.
Parameters
- hSocket
- The socket handle.
- nAddressFamily
- An integer which identifies the type of IP address to return.
It may be one of the following values:
| Constant |
Description |
| INET_ADDRESS_UNKNOWN |
Return the IP address for the specified host in either IPv4
or IPv6 format, depending on the type of connection that was
established. If the hSocket parameter is INVALID_SOCKET,
a preference will be given for returning an IPv4 address.
However, if the local host only has an IPv6 address, that value
will be returned. |
| INET_ADDRESS_IPV4 |
Specifies that the address should be returned in IPv4
format. The first four bytes of the ipNumber array are
significant and contains the IP address. The remaining bytes
are not significant and an application should not depend on
them having any particular value, including zero. |
| INET_ADDRESS_IPV6 |
Specifies that the address should be returned in IPv6
format. All bytes in the ipNumber array are significant.
Note that it is possible for an IPv6 address to actually
represent an IPv4 address. This is indicated by the first 10
bytes of the address being zero. |
- lpAddress
- A pointer to an INTERNET_ADDRESS
structure that will contain the IP address of the local host. If the
hSocket parameter is specified as INVALID_SOCKET, this function
will attempt to determine the IP address of the local host assigned by
the system. If the address is not required, this parameter may be
NULL.
- lpnPort
- A pointer to an unsigned integer that will contain the local
port number. If the hSocket parameter specifies a valid
socket, this parameter will be set to the local port that the
socket was bound to. If the hSocket parameter is specified
as INVALID_SOCKET, this parameter is ignored. If the port number is
not required, this parameter may be NULL.
Return Value
If the function succeeds, the return value is zero. If the
function fails, the return value is INET_ERROR. To get extended error
information, call InetGetLastError.
Remarks
To ensure future compatibility with IPv6 networks, it is important
that the application does not make any assumptions about the format
of the address. If the function returns successfully, the
ipFamily member of the INTERNET_ADDRESS structure
should always be checked to determine the type of address.
If the nAddressFamily parameter is specified as
INET_ADDRESS_UNKNOWN, the application must be prepared to handle IPv6
addresses because it is possible for the local host to have an IPv6
address assigned to it and no IPv4 address. For legacy applications
that only recognize IPv4 addresses, the nAddressFamily member
should always be specified as INET_ADDRESS_IPV4 to ensure that only
IPv4 addresses are returned.
If the system is connected to the Internet through a local network
and/or uses a router that performs Network Address Translation (NAT), the
InetGetLocalAddress function will return the local,
non-routable IP address assigned to the system. To determine the
public IP address has been assigned to the system, you should use the
InetGetExternalAddress function.
Requirements
Minimum Desktop Platform: Windows 7 (Service Pack 1)
Minimum Server Platform: Windows Server 2008 R2 (Service Pack 1)
Header: Include cswsock10.h
Import Library: cswskv10.lib
See Also
InetGetExternalAddress,
InetGetHostAddress,
InetGetHostName,
InetGetLocalName,
InetGetPeerAddress,
INTERNET_ADDRESS
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